Community surveys of healthcare-use determine the proportion of
illness episodes not captured by health facility-based surveillance, the
methodology used most commonly to estimate the burden of disease in
Africa. A cross-sectional survey of households with children aged less
than five years was conducted in 35 of 686 census enumeration areas in
rural Bondo district, western Kenya. Healthcare sought for acute
episodes of diarrhoea or fever in the past two weeks or pneumonia in the
past year was evaluated. Factors associated with healthcare-seeking were
analyzed by logistic regression accounting for sample design. In total,
6,223 residents of 981 households were interviewed. Of 1,679 children
aged less than five years, 233 (14%) had diarrhoea, and 736 (44%) had
fever during the past two weeks; care at health facilities was sought
for one-third of these episodes. Pneumonia in the past year was reported
for 64 (4%) children aged less than five years; 88% sought healthcare at
any health facility and 48% at hospitals. Seeking healthcare at health
facilities was more likely for children from households with higher
socioeconomic status and with more symptoms of severe illness. Health
facility and hospital-based surveillance would underestimate the burden
of disease substantially in rural western Kenya. Seeking healthcare at
health facilities and hospitals varied by syndrome, severity of illness,
and characteristics of the patient.

Nearly 10 million children in developing countries die each year
before reaching five years of age, mostly from pneumonia, diarrhoea, and
malaria (1,2). Implementation of proven interventions would reduce
mortality due to these common childhood illnesses (3-7). However, the
potential impact of such interventions in different locations in Africa
is difficult to estimate without accurate local disease-burden data.
Obtaining such estimates is challenging in much of Africa where ill
children often never access formal healthcare, and most deaths occur at
home (8,9). Accurate estimates of the burden of diseases are needed to
set public-health priorities for allocation of resources.

Health facility-based surveillance of diseases is the most common
method for assessing the burden of diseases. Facility-based surveillance
allows verification of signs and symptoms by trained clinicians and
simplifies collection of specimens to confirm diagnoses. Despite these
advantages, facility-based surveillance underestimates the actual burden
of diseases in places where healthcare-use is poor. Results of
healthcare-use surveys can be used for adjusting facility-based
measurements of the burden of diseases (10-12). Healthcare-use surveys
can also inform policy-makers about the potential impact of
facility-based interventions, such as Integrated Management of Childhood
Illness (IMCI) (13,14).

To guide local decisions about the type of surveillance to be
conducted for infectious disease syndromes in a rural district in
western Kenya, we carried out a community survey of healthcare-use for
acute episodes of fever, respiratory illness, and diarrhoea among young
children and their household members. We estimated the proportion of
acute episodes likely to be captured by a health facility- and
hospital-based surveillance.

MATERIALS AND METHODS

Study setting

The survey was conducted in Bondo district in rural western Kenya.
The district has borders with Lake Victoria and includes several
islands. The total population of the district was approximately 239,000
in 1999 (15). The population is predominantly of Luo ethnicity.
Subsistence farming and fishing are the main economic activities. The
prevalence of HIV is among the highest in Kenya (11% in men aged 13-34
years and 21% in women aged 13-34 years in 2003) (16), and malaria is
hyperendemic (17). In 2005, the rate of mortality of children aged less
than five years from a demographic surveillance system in part of Bondo
district was 227 per 1,000 livebirths (18). The district has eight
inpatient facilities and 45 outpatient facilities.

Study design

In August 2005, a sample of households with at least one child aged
less than five years (under-five child) was obtained by cluster
sampling. The 49 sublocations, comprising 686 enumeration areas within
Bondo district (the primary sampling units), were ordered
geographically, and 31 sublocations were selected with replacement by
probability proportional to estimated total population. In total, 35
enumeration areas were randomly chosen from the 31 sublocations
included. Enumeration area-boundaries were defined by the Kenyan Bureau
of Statistics for the 1999 national census (19). The number of
households per enumeration area ranged from 39 to 199 (median 84).

Trained interviewers visited all households within the selected
enumeration areas to identify households with under-five children.
Households in which an under-five child resided but for which the
child's primary caretaker was not present were revisited once and
were treated as non-respondent households if a caretaker was not present
on revisit. All the households with an under-five child and a primary
caretaker present were included in the sample for all selected
enumeration areas. For the enrolled households, interviewers
administered questionnaires in the local language (dho-Luo) to collect
demographic and socioeconomic information, including the educational
level of caretakers, primary source of income, access to potable water,
and household possessions.

Adult caretakers were asked to identify episodes of acute diarrhoea
or fever within the preceding two weeks for all household members.
Diarrhoea was defined as three or more loose stools within a 24-hour
period. Fever was subjective as perceived by the caretakers. Caretakers
were also asked to identify episodes of acute respiratory illness within
the preceding 12 months characterized by cough and difficult breathing
for more than two days or a diagnosis of 'pneumonia' by a
healthcare worker. The respiratory screening questions were based on the
definition of probable pneumonia episodes from a validation study of
verbal autopsies that included children who died of pneumonia (20). We
felt that this definition based on verbal autopsies was likely to
capture severe respiratory illness, more likely to be pneumonia. Since
we focused on pneumonia, which is relatively rare compared to fever and
diarrhoea, we asked about acute respiratory illness in the past 12
months, rather than two weeks. We found that the large majority (71%) of
reported respiratory illness episodes occurred less than two weeks
before the interview. We also found that the severity of acute
respiratory illness was greater for more distant episodes compared to
episodes that occurred during the past two weeks (see Results section).
Because of these findings, we assumed respiratory illness episodes that
occurred more than two weeks in the past were more likely to be
pneumonia whereas episodes in the past two weeks were more likely to
capture milder respiratory illnesses. Therefore, for analysis, we
classified episodes that occurred in the past two weeks as acute
respiratory illness (ARI) and episodes in the past 12 months (excluding
the past two weeks) as pneumonia.

For each household member with a reported disease episode,
caretakers were asked detailed questions about symptoms and healthcare
sought, including sources of care, diagnostics performed, treatment
received, and whether the household member was hospitalized. Reported
visits to healthcare facilities for illness episodes were not validated
by crosschecking with facility registers.

Sample-size

The sample-size was calculated to provide a precision of at least
[+ or -]0.20 for the proportion of under-five children who sought care
at a health facility for an episode of pneumonia in the past 12 months
(which was expected to be the least common of the clinical syndromes
studied). The survey was designed to include visits to approximately
2,900 households based on the assumptions that 50% of such children
would have sought medical care, that 5% of children would have had an
episode of pneumonia in the past 12 months, and that 33% of households
would have an under-five child. Healthcare-seeking behaviour for each
syndrome was assumed to be independent. For children with more than one
reported illness episode of the same syndrome, respondents were asked
about healthcare sought for the most recent episode. A design effect of
2 was assumed, thus doubling the estimated number of children to be
surveyed.

Statistical analysis

Analysis of data was performed using the SAS software (version 9.1)
(SAS Institute Inc., Cary, NC, USA) and SUDAAN release 9.0 (version 7.5)
(Research Triangle Institute, NC, USA) to account for clustered sample
design and correlations between individuals from the same household.
Self-weighting was used based on the probability proportional to size
(PPS) sampling scheme. The %2 test was used for differences in
proportions. Multivariate logistic regression was used for identifying
the factors independently associated with healthcare-seeking behaviours.
Dichotomous independent variables included in each multivariate model
were: gender, age (<1 year vs 1-4 years for models pertaining to
under-five children), household socioeconomic status (defined according
to the number of household goods owned), educational level of
caretakers, and severity of illness (defined according to the number of
symptoms of severe illness reported) (detailed definitions are in Table
4).

Ethical approval

The ethical review committees of the Kenya Medical Research
Institute (KEMRI) and the U.S. Centers for Disease Control and
Prevention (CDC) approved the study.

RESULTS

Visits were made to 2,810 households (97% of households in selected
enumeration areas); a primary caretaker was available for interview in
2,360 (84%) households. Of the 2,360 households, 1,009 (43%) had at
least one under-five child. Caretakers of 28 (2.8%) households refused
to participate. In total, 1,679 under-five children were included from
981 households with an under-five child, and 4,544 persons aged over
five years in these households were also included (Table 1).

In the participating households, 85% of primary caretakers were
female, and 44% had not completed primary school. Forty-one percent of
the households were classified as of higher socioeconomic status; radios
(79%), bicycles (63%), and furniture (54%) were the most common
possessions. Most (86%) households relied on surface-water for drinking,
and 59% used pit-latrines (the remainder had no toilet).

Of the 1,679 under-five children, 14% [95% confidence interval (CI)
12-16] had diarrhoea, and 44% (95% CI 41-46) had subjective fever in the
past two weeks (Table 1). The median duration of episodes of diarrhoea
was three days, and the median duration of fever was four days.
Thirty-one percent (n=72) of children with diarrhoea and 26% (n=191) of
children with fever met our criteria for severe illness episodes.

Episodes of respiratory illness were reported for 222 (13%) of the
1,679 under-five children, the majority (n=158; 71%) of whom had illness
onset--categorized as ARI--in the two weeks preceding the interview.
Compared to ARI episodes, respiratory illness episodes that occurred
more than two weeks in the past--categorized as pneumonia--were
significantly more likely to have included wheezing (94% for pneumonia
vs 79% for ARI; p=0.01), to have met our criteria for severe respiratory
illness (40% vs 20%; p=0.01), to have been hospitalized (26% vs 7%;
p< 0.01), and to have been diagnosed with pneumonia by a healthcare
worker (86% vs 18%; p<0.01). ARI episodes also tended to have lower
mortality (2%) than pneumonia episodes (8%; p=0.06).

All illness syndromes were reported less frequently among household
members aged five years or older compared to under-five children (Table
1).

Of the under-five children, complete data on healthcare-seeking
behaviour were available for 78% of respiratory illness episodes, 81% of
diarrhoeal episodes, and 81% of febrile episodes (syndromes not mutually
exclusive). Treatment at a health facility was sought in 35-42% of
illnesses that occurred during the preceding two weeks (Table 2). Care
was slightly more commonly sought at hospitals for ARI (18%, 95% CI
12-26) than for diarrhoea (8%, 95% CI 5-13) or fever (11%, 95% CI 9-14).
Common sources of healthcare-seeking outside the household for ARI,
diarrhoea, or fever were drug-sellers (range 39-45%) and private care
providers (range 22-24%). A relatively few children visited traditional
healers (range 3-7%) or village health volunteers (range 5-6%) (Table
2).

For pneumonia episodes in the preceding 12 months (excluding ARI in
the preceding two weeks), the caretakers reported seeking healthcare
outside the home for all episodes. Significantly more of these episodes
resulted in visits to health facilities (88%, 95% CI 76-95), visits to
hospitals (48%, 95% CI 3562), and hospitalizations (26%, 95% CI 16-40)
than for ARI in the past two weeks (Table 2). Of the 13 children with
reported pneumonia who were hospitalized, nine (69%) had first visited
an outpatient health centre for care.

Diagnostic procedures were uncommonly reported for all syndromes.
Of children with febrile illnesses, blood smears were reported for 17%
of episodes. Chest radiographs for pneumonia and tests of stool
specimens for diarrhoea episodes were performed in 6% and 2% of episodes
respectively (Table 2). In contrast, intake of antibiotics and
antimalarials was common. Of children with ARI, diarrhoea, or fever in
the past two weeks, 61%, 62%, and 56% took an antibiotic and 59%, 52%,
and 61% took an antimalarial drug respectively. Children with any of the
reported illnesses often received herbal remedies (range 34-40%) or were
prayed for with regard to their illness (range 26-40%) (Table 2).

Compared to under-five children, other household members aged five
years or older had generally similar patterns of most healthcare-seeking
behaviours (Table 3). However, persons aged over five years visited
health facilities less often than young children for episodes of
pneumonia (66% vs 88%, p=0.01).

Table 4 shows the proportions of under-five respondents with
syndromes of interest who visited health facilities, stratified by
gender, age, socioeconomic status, educational level of caretakers, and
severity of illness. In multivariate analyses, including all these
factors simultaneously, household socioeconomic status and severity of
illness were independently associated with seeking healthcare at health
facilities (significant independent associations are denoted by single
asterisks in Table 4). For pneumonia episodes, children in households
with higher socioeconomic status were more likely to be taken to any
health facility [adjusted odds ratio (AOR)=21.8, 95% CI 1.0-456.9] or to
be taken to a hospital (AOR=4.1, 95% CI 1.4-12.2) and be hospitalized
(AOR=7.3, 95% CI 1.1-48.1). Children with more severe pneumonia were
more likely to be taken to a hospital than children with less severe
pneumonia (AOR=5.9, 95% CI 1.4-25.2). For diarrhoea episodes, higher
socioeconomic status was associated with seeking healthcare at a
hospital (AOR=3.4, 95% CI 1.0-10.8). For febrile episodes, more severe
illness was associated with more hospitalizations (AOR=3.7, 95% CI
1.4-9.4). Healthcare was more often sought for male children, although
the differences were not significant (Table 4). Of other household
members aged five years or older, households with higher socioeconomic
status were associated with a higher probability of visiting any health
facility for febrile illness; greater severity of illness was associated
with a higher probability of visiting any health facility for febrile
illness and a higher probability of visiting a hospital for pneumonia
(data not shown).

DISCUSSION

This study of healthcare-seeking behaviours in rural Kenya
demonstrated that the proportions of illness episodes captured through
health facility-based surveillance would vary for different clinical
syndromes and surveillance settings. Based on our survey data,
surveillance encompassing all healthcare facilities (including
outpatient clinics) in Bondo district would capture roughly 30-40% of
episodes of diarrhoea, febrile illness, and ARI in under-five children
and a larger proportion (approaching 90%) of pneumonia episodes.
However, surveillance restricted to inpatient hospitals would capture a
much smaller proportion of episodes, from roughly 50% of children with
pneumonia to 1020% of children with less severe respiratory illness,
diarrhoea, or malaria. As expected, adults included in the survey less
commonly sought care at facilities than children, even for episodes
classified as severe.

The prevalence of acute illnesses and patterns of health
facility-use for under-five children in this study were similar to other
data from Kenya. In the 2003 Demographic and Health Survey, rates of
prevalence for acute illness episodes among young children in the past
two weeks were 18% for ARI, 41% for fever, and 16% for diarrhoea (19).
Treatment was sought at a healthcare facility for 46% of those with ARI
and 30% of those with diarrhoea, of whom 29% received oral rehydration
salts. In another study in Kakamega district in rural western Kenya,
treatment was sought in health facilities for 27% of preschool children
with cough or 'cold' in the past week, 33% of those with
fever, and 40% of those with acute diarrhoea (21). Children may not be
taken to hospitals for severe illness episodes for various reasons.
Caregivers may not recognize signs and symptoms of severe illness,
hospitals may be very far or very costly, or healthcare workers may not
refer sick children (22). Higher levels (87%) of hospital-use were found
in a rural province in Thailand among children aged less than 14 years
with self-reported pneumonia in the past year (10). In middle-income
countries, such as Thailand, with good access to hospitals even in rural
communities, adjustment for local healthcare-seeking behaviours are
likely to result in smaller increases in facility-based estimates of
pneumonia incidence than in rural African settings.

A similar, contemporaneous community survey of healthcare-use among
children was conducted in a crowded informal settlement in Nairobi (23).
The use of healthcare facilities was higher in the urban site than that
in the rural site for recent episodes of diarrhoea and of fever among
under-five children. The greater use of healthcare in the urban area
might be related to the shorter distances needed to be travelled to
visit a health facility or a higher level of education, socioeconomic
status, or health awareness among the urban population (24). In
contrast, frequency and sites of healthcare-seeking for pneumonia and
ARI among under-five children were similar in the urban and rural sites
in Kenya, with the exception of the fact that children in Bondo district
were more often taken to private care providers. Why healthcare-seeking
was not more common in the urban site for respiratory illness as it was
for fever and diarrhoea is not clear but could be related to differences
in the definitions of pneumonia and ARI used in the two studies.

Our study demonstrated that the poorest segments of the community,
who are likely at the highest risk of disease, are likely to be
under-represented in facility-based surveillance data. Other studies in
both rural and urban areas of sub-Saharan Africa have documented similar
associations between socioeconomic indicators and healthcare-seeking
behaviours for young children, even in environments that might appear
uniformly impoverished (13,21,25). We also observed trends towards
increased hospital-use for boys compared to girls; although not
statistically significant, this is consistent with trends noted in other
poor communities in Kenya (25). Although distance to health facilities
was not evaluated in this survey, distance was an important determinant
of healthcare-seeking behaviour for pneumonia and other syndromes in
other studies (26-28). Understanding the determinants of
healthcare-seeking at health facilities is necessary to interpret
results of facility-based surveillance as those who access facilities
might not be representative of the general population.

Limitations

This study had several limitations. Syndromes were defined based on
reported symptoms and were not verified by medical examinations. For
example, in malaria-endemic areas, signs and symptoms of pneumonia and
malaria in children overlap (20,29). Second, caretakers' recall of
specific symptoms and healthcare-seeking behaviours may be unreliable,
particularly with regard to the reported pneumonia episodes that
occurred up to 12 months before the survey. Third, the sample of older
children and adults included in the survey was restricted to those
living with under-five children and may differ in the burden of disease
and healthcare-seeking practices from older children and adults in
households without under-five children. Fourth, the socioeconomic status
metric used in our multivariate analyses was limited to a single
dimension of wealth (household goods owned) and was not externally
validated. Last, because of small numbers of respondents in some
categories, the precision of AORs from our multivariate analyses was
low. Nevertheless, we observed significant independent associations that
highlight sub-populations at an increased risk of being missed by
facility-based surveillance for the syndromes of interest. Additional
research is needed to more closely examine the magnitudes of these
associations.

Conclusions

We found that facility-based surveillance, particularly using
hospitals as the catchment sites, would underestimate the true burden of
infectious diseases in settings like Bondo district in rural western
Kenya. Moreover, facility-based surveillance will differentially
underestimate the burden of diseases, based on characteristics of the
disease (e.g. severity) and the person (e.g. socioeconomic status and
sex). Data from community healthcare-use surveys such as ours may be
used for guiding public-health surveillance strategies. For instance,
based on local healthcare-use data, surveillance programmes that seek to
define the burden of diseases or study aetiologies might consider
capturing illness episodes outside facilities, such as at drug-shops and
homes, to better estimate the full spectrum of a disease. Moreover, if
facility-based surveillance is conducted, community healthcare-use
surveys can improve interpretation of surveillance data by providing an
adjustment factor that accounts for the proportion of illness episodes
for which care is not sought at health facilities. In this way, local
healthcare-use data may play an important role to better inform
policy-makers on the true burden of diseases to be used in the planning
of interventions and evaluation activities.

ACKNOWLEDGEMENTS

This paper is approved with the permission of the Director, KEMRI.

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